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Solve the top equation to get on variable on one side
2x-y=6
-y=-2x+6
y=2x-6
then plug in the coordinate for x and y for both equations. if both equations are true then it’s a solution
2=2(2)+6
2=10
4+2=6
so it’s not a solution
In the middle:
x-coordinate= {7-(-1)}/2= 4
y-coordinate= (8-2)/2= 3
So centre is (4,3)
Answer:
D
Step-by-step explanation:
Using the Cosine rule to find AC
AC² = BC² + AB² - (2 × BC × AB × cosB )
= 18² + 12² - ( 2 × 18 × 12 × cos75° )
= 324 + 144 - 432cos75°
= 468 - 111.8
= 356.2 ( take the square root of both sides )
AC =
≈ 18.9
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Using the Sine rule to find ∠ A
=
( cross- multiply )
18.9 sinA = 18 sin75° ( divide both sides by 18.9 )
sinA =
, then
∠ A =
(
) ≈ 66.9°